After manufacture, paper such as newsprint paper is conventionally wound on hollow cylindrical core members of paperboard material which, for winding paper thereon to form a roll and unwinding paper therefrom, are mounted on winding or unwinding equipment which has a pair of spaced stub-chucks which engage in opposite ends of a tubular core member. To prevent the core member itself from being damaged by the stub-chucks, it is also conventional to provide the ends of the tubular core members with some kind of reinforcement. A common type of reinforcement comprises a tubular cap member of sheet metal with a U-shaped section which fits over an end of the core member such that an inner annular wall of the cap member engages the inner wall of the core member and an outer annular wall of the cap member engages the outer wall of the core member.
Particular problems arise when paper is being unwound from a roll and fed to a printing press. To maintain a desired tension in the paper being fed to a printing press, it is necessary to provide means to apply a braking force to the roll. This is usually done by providing a braking force to one of the stub-chucks which transmits the braking force to the core member. At least one stub-chuck at an unwinding station may be provided with one or more keys which engage in one or more notches in an end of the core member and/or cap member or may be provided with axially extending splines which engage the inner surface of a core member which has no end reinforcement.
Unfortunately, a metal cap member being isotropic will assist in transmitting cyclical shocks from a stub-chuck and chuck key to an unwinding paper web, especially after chuck wear has occurred with resultant deterioration in the quality of printing on the paper web. Also, splines on a braking stub shaft tend to damage the inner surface of the core member, with resultant loss of proper braking control and resultant deterioration of print quality.
It is therefore an object of this invention to provide a tubular core assembly which at least substantially overcomes these problems.